The invention relates, in general, to a chemical oxygen generator and, more particularly, to a new and useful chemical oxygen generator of the type having a manually triggerable starting device.
Chemical oxygen generators are used in respirators to make a supply of oxygen available. The oxygen in chemical oxygen generators is typically present in a chemically bound state, such as in a chlorate candle or in a KO.sub.2 cartridge, which is released, when needed, in the course of a chemical reaction. A starting device triggers the oxygen discharge by manual release. Several seconds are always lost before the oxygen discharges in the full amount required. This represents a difficulty for respirator applicators as a user cannot be immediately supplied with the required breathable gas.
A known oxygen generating call unit, housed in a dispensing apparatus, has a one-way tank such as of tin plate, with a cylindrical sidewall, a closed bottom face wall and an upper face wall broken by a central opening. The opening is tightly closed by a pierceable foil seal. An oxygen candle of compressed sodium or potassium chlorate, to which a sodium or potassium oxide is admixed, is retained in the tank by means of elastic fiber mats in such a manner that its flat sides are spaced from the tank wall so that flow paths for the developing oxygen remain. At the tip of the candle is an ignition cone, centered with respect to the opening in the upper tank face wall.
The dispensing apparatus in which the cell unit is accommodated, contains a concentrically encompassing cylindrical sidewall and one each perforated bottom and top wall. The latter has a shiftable thrust bolt and a cup-type lock spaced from the thrust bolt all around, with an oxygen discharge tube leading to the outside.
To activate the oxygen generator cell unit, the thrust bolt is pushed through the foil seal in the upper face wall of the cell tank, and a glass vial above the ignition cone is smashed. The ignition cone is activated, and it, in turn, then initiates burning of the oxygen candle. The oxygen then freed flows through the flow paths between the tank and the oxygen candle and through the cup-type lock into the oxygen discharge tube.
It is advantageous that the oxygen formed is not available the moment the chemical reaction is triggered. Several seconds (up to 10) always pass, and this applies also to the other known ignition system with primer or electrical incandescent wire, before the oxygen generator reaches its full rated output. Therefore, this known oxygen generator cell unit is not suited for applications where the oxygen is needed immediately, e.g. as emergency supply in aircraft or oxygen breathing apparatus carried on the user's body (see West German Auslegeschrift No. 26 20 300).